Smart Houses – HEMS Initiatives –— Certification of Smart Meter Communication —Masao Isshiki

Professor, Department of Home
Electronics, Kanagawa Instituteof Technology
Director, HEMS Certification
Support Center

1. Introduction
This article introduces the situation of smart electric energy
meters in Japan, especially with regard to their certification.
Since meters are thought to be a key element of smart houses,
it has been decided that they must be able to work closely withHEMSs (Home Energy Management Systems). However, meters
are only provided by electric power companies, whereas HEMS
services will be provided by other companies via open markets.
This means that the meters are public goods installed in all houses
and shared by many related businesses. In this regard, securing theinteroperability and communication performance of these devices
is of key importance in creating an environment for cooperativeservices.
A smart meter consists of three parts: (1) an electric power
meter that has been certified based on the Measurement Act, (2)a communication unit that carries information between the meterand the electric power company (using communication methods
specific to this particular company), and (3) a communication■ Figure 1: Routes for Smart Meter Communication

8New Breeze Spring 2015

Yuji Sasagawa

Research Staff, Smart House
Research Center, Kanagawa
Institute of Technology

unit that provides data to the HEMS. As previously described,
the communication units for (3) must all use the same standard
protocol defined by the industry in Japan, and are required to pass
SMA certification (to certify compliance of the smart meter’sapplication layer) to ensure conformity.
SMA certification has been in operation since April 2014. As
a result, certified smart electric energy meters have been installedin limited areas since September 2014 by Tokyo Electric Power
Co., Inc., and since the October 2014 by Chubu Electric Power
Co., Inc.
The following sections present the background of smart meter
certification, the framework of the certification, and the future
prospects.

2. Background: Smart Meter Route B
In this section, we first explain what are meant by the terms“smart meter” and “route B”, and we discuss the significance ofroute B (the target of the certification).

■ Figure 2: The position of ECHONET Lite in a HEMS

A smart meter is generally defined as an electronic meterthat is equipped with a bidirectional communication functionthat allows the electric power company to read the meter and,if necessary, operate a breaker remotely. Such meters are also
expected to create cooperative services with HEMSs.
A more detailed description can be found in a report by theSmart Meter System Study Group [1], which was established inMay 2010 to discuss the basic concepts of smart meters, theirintroduction, and their future prospects. This report set thedirection of smart meter deployment in Japan and triggered theirintroduction.
The smart meters being introduced on a wide scale in Japan arecapable of cooperating with HEMSs. Another significant pointis that all smart meters communicate using the same protocol,
allowing any private company or electric power companies toaccess the same information in a common format. It is therefore
no exaggeration to say that the smart meters in Japan are
revolutionary, cutting-edge devices.
Here we describe the communication routes whereby data is
obtained from smart meters. Currently, there are three routes,
called routes A, B and C. Figure 1 shows a conceptual illustrationof each route.
These routes were set forth in the report by the Smart Meter
System Study Group. Route A is the route used by electric powercompanies, mainly to obtain meter data for billing. Route B is a
newly introduced route, with which the meter data can be obtained
directly from the meter by household equipment. Route B has thefollowing three noteworthy characteristics:i) Its data is no different from the data obtained via route A(i.e., identical to the electric power meter information forbilling).
ii)	Ordinary consumers are able to obtain this data withrelatively little expense and effort.
iii) It provides better real-time data on electric power
consumption than route A.
Point i) was published in the distributed material of the 14th
Smart Meter System Study Group meeting, and was underwrittenby the Ministry of Economy, Trade and Industry. For electricity
providers, especially new entrepreneurs, this is the most important
point in researching businesses that utilize the route B information.
Of course this information is also useful for helping ordinary
consumers save on their electricity bills.
As for point ii), a HEMS controller device that has gained
SMA certification for route B is necessary to obtain data from thesmart meter. In general, route B communication is scheduled tostart earlier than route A. (Figure 2)
Those characteristics are premised on an open standard andsecured by third-party certification. The communication protocolin route B, ECHONET Lite, is an open standard, which meansthat all sorts of information related to route B are published, andthe essential data set is identical across the smart meters of allelectric power companies. The ECHONET Lite specifications
are published by the ECHONET Consortium [2]. Guidelines
to the configuration and operation of route B have also beenpublished by a committee [3]. It has thus been ensured that all thenecessary information for conducting business related to route B is
publicly available.
With regard to point iii), it is worth noting that route B also
provides data on the instantaneous electric power consumption,
which shows how much electricity is being consumed by theNew Breeze Spring 20159

whole household at any particular moment. This information isalmost useless without real-time handling, so route B is the only
way it can be delivered. As described in the use cases shown in
the guidelines, if consumers are presented with information about
their instantaneous power usage through a HEMS (or are able tofetch this information at will), then they can be expected to takeenergy/electricity-saving actions such as turning off unnecessary
appliances or adjusting the temperature settings of air conditioners.
Alternatively, a warning message can be issued when too muchelectricity is being used, which can be useful for preventing circuit
breakers from tripping unexpectedly.
The other information that can be obtained via route B, suchas the cumulative energy consumption measured at every fixed
period of time, and the current time, are fixed so as to be identicalto the information used for billing that is obtained via routeA. Other information related to billing, such as billing rates, is
not currently available via route B, although new entrepreneurs
entering the electricity retail business are expecting this situation■ Figure 3: SMA certification test system

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to change in the future.

3. Framework of Route B Certification
So far we have explained the characteristics of smart electricpower meters and route B. In this section, we describe theframework of certification according to the guideline [3].
A key point is that it requires the following three forms ofthird-party certification:i) Certification of the lower communication layers (mediapart),ii)	ECHONET Lite certif ication (protocol layer ofECHONET Lite), andiii)	SMA certification (application layer of ECHONET Lite).
For i), the guidelines specify eligible methods for the physicallayer and the layers below layer 4, and two methods are adopted
by the electric power companies. The primary communication
method is 920 MHz wireless communication (Wi-SUN(IP)) andthe complementary method is power-line communication (G3-PLC). A third-party certification test ensures conformity up tolayer 4 (UDP) including the physical layers. Certification of bothcommunication methods has already started.
For ii) and iii), the HEMS Certification Support Center at
Kanagawa Institute of Technology has been named as the thirdparty certification organization by the ECHONET Consortium[4], and started providing certification in April 2014. For thepurpose of securing conformity and interoperability, the center
requires that the actual devices are submitted for both smart meterand HEMS controller testing.
Figure 3 shows the configurations of the SMA certification
test system.
Note that all the three certifications must be granted in
the correct sequence. After successfully completing the SMA
certification test, a registration certificate is issued and the device
is publicly listed on the ECHONET Consortium web site.
As of 12th February 2015, there are already 19 devices thathave achieved SMA certification and registration (eleven smart
meters and eight HEMS controllers), and this number will growsteadily when smart meters are introduced in earnest.
The HEMS Certification Support Center at Kanagawa
Institute of Technology is also performing interoperability tests(IOTs) on SMA certified and registered devices. By introducing
the actual smart meters from multiple electric power companies, anIOT laboratory is provided to the applicants for SMA certification.
These interoperability tests are indispensable to developers because
they make it possible to provide customers with services that arereliable but are also differentiated from the services offered byother companies.

4. Future Prospects
Environmental measures for the full-scale introduction ofsmart meters are now in an advanced stage of preparation. From
now on, service providers are expected to clearly present the meritsof improved interoperability. The government’s involvement willprobably shift towards the study of new services valuable toconsumers, and how to facilitate those businesses.
Converting the smart house market to an open platformbusiness is essential for the growth of this market. ECHONET
Lite is an open platform and occupies a key position. The
government is focusing its efforts on the cultivation of new
business associated with smart houses through this platform.
In the future, it is expected that various new forms of businesswill emerge to make use of electricity usage data, especially data
gathered through smart meters and HEMSs, and to provide

related services. In particular, since there will have to be many
services rooted in a particular region, we think that there is apressing need for the cultivation of HEMS integrators that canrespond to the needs in each region and provide their residents
with the services they require. This is a new form of business thatis expected to create circumstances that will cultivate housing
ventures in housing business areas. This would take the form ofa HEMS integrator service as a professional fusion of network
technology and residential services.
The introduction of smart apartment blocks (condominiumenergy management system; MEMS) is also being promoted.
The smallest unit of a MEMS is a HEMS, and the application of
ECHONET Lite to small-scale BEMS such as tenant buildings
is also being studied. In the future, this market is expected to growin the same way as for smart houses.
At the same time, the emergence of many products andservices that are useful to users (residents) will also be required.
It is essential to create “living innovation” in order to realize
smart houses that are of value to the people that live in them.
It is essential for smart houses to provide a new kind of living
environment that nobody has experienced before, where household
electrical appliances, facilities and IT equipment work together
cooperatively.
Finally, we would like to send a message to all businesses thatare responsible for the growth of smart houses in the future.
As a major step towards the introduction of smart housesthroughout Japan, smart house (HEMS) businesses based on
the ECHONET Lite open standard interface have now started.
This highly significant development demonstrates that initiatives
such as the use of open standards, the open publication of various
guidelines, and the creation of a third-party certification scheme
have resulted in an environment where anyone can participate, andin the future we will promote activities to facilitate the creation ofan open HEMS platform that will benefit everyone.
We are looking forward to seeing how things turn out in thefuture.
REFERENCES[1] Report of the Smart Meter System Study Group(http://www.meti.go.jp/committee/summary/0004668/report_001_01_00.pdf)[2] ECHONET Consortium(http://www.echonet.gr.jp/index.htm)[3] HEMS-Smart Meter B Route (Low Voltage Electricity Meter) Operating Guidelines [version
2.0](http://www.meti.go.jp/committee/kenkyukai/shoujo/smart_house/pdf/006_s03_00.pdf)[4] Smart House Research Center Web Site
(http://sh-center.org/hemsinfo/1755)

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